The present invention relates to a microphone unit for use with a portable two-way radio transceiver, for enabling oral communication via the radio transceiver, said microphone unit including a locating device for enabling said radio transceiver to transmit a signal containing position locating information.
In particular, but not exclusively, the invention relates to an alarm device which, when utilised in conjunction with a separate radio transceiver, provides that transceiver with features which did not previously exist. These additional features enable the location of the user of that transceiver to be determined automatically or manually, independently of or as a result of the activation of an alarm, either directly or indirectly. This location information may be reported to the user of the hand held radio, other system users or a central controller. The added device will therefore provide the transceiver with a number of very useful features which may not have been originally incorporated within the original product at a very economic cost.
Prior art devices which exist are described by patent No. GB 2 051 444B (Ericsson), patent No. GB 2 223 869B (Tunstall) and patent application No. GB 2 223 380A (Shorrock Ltd). Ericsson discloses a system including a receiver unit and a transmitter unit, which when enabled transmits a location code and an identification code. The system also includes a number of strategically placed low power transmitter devices which due to their location and low power are able to be related to a specific area within a building.
These location transmitters would typically be placed near each door within a building, each would have a unique identity and a range of typically 5 meters. When the portable device is within range of the location transmitter it will receive and store the location information. In the event that the alarm transmitter is activated, the transmitter sends its own unique identification together with the stored identity of the last received location transmitter.
A central receiver can then process this information and with a reasonable degree of certainty determine the location of the person who activated the alarm.
Tunstall suggests a number of improvements to the Ericsson art, such improvements include the ability of the portable transmitter device to receive and store information from a plurality of location transmitters together with additional coding to enable a more accurate location fix to be determined, particularly if the system is required to operate within a building having more than one floor. A further improvement includes the ability of the local transmitter to initiate the portable alarm transmitter automatically by means of a modified location identity code.
Shorrock discloses technology which is very similar to Ericsson, however in this instance the location identifying units are interrogated to initiate the emission of the location information. An alternative embodiment makes use of well known bar code reading technology to determine the location of the individual.
All of the described prior art comprises a self contained alarm transmitter with integral locating device receiver/interrogator which can send an alarm signal together with the location of an individual in distress. Additional product exists within the market (hereinafter also referred to as prior art) which utilises the same technology, however the hand held alarm unit also includes a microphone and speaker arrangement with a receiver so that the unit can also be used for two way speech.
Since such products effectively comprise a two way personal radio with the locating technology combined within the one unit they tend to be very expensive when compared with standard two way radio transceivers.
A major disadvantage with the prior art is that any organisation wishing to provide their staff with an alarm system which utilises this type of location reporting technology must purchase this implementation of the technology even though they may already have an existing system utilising portable two way personal radio equipment. The lack of compatibility between the two systems is clearly undesirable.
Furthermore, the prior art alarm technology disclosed generally uses low power radio transmitters because the radio regulations stipulate certain frequencies must be used for such alarm equipment and the authorities only permit low power transmitters to be used on such frequencies. This results in a significant amount of system infrastructure being required in the event that a large site such as a shopping centre, large industrial facility or a prison is in need of protection.
Patent No. GB 2 247 761 A (Davis) discloses an alarm interface which is applied to a modified PCN (personal communications network) handportable. Davis suggests that the potential location of the handportable can be determined by virtue of the cell being used within a cellular radio network. This approach has two major disadvantages. The first being that the handportable needs to be modified. Modification can be expensive (if even possible), more importantly radio transmission equipment requires radio regulatory type approval testing, and such regulatory approval is invalidated upon modification of the approved product unless it is re-submitted for type testing. This is a very expensive process for hand portable radios and cellular radio equipment in particular. This option is clearly impractical for users of existing systems.
A second disadvantage is that it is only possible to identify location within the general coverage area of a cell. In a city typical cell coverage might be two kilometers in diameter which results in a totally inadequate positional resolution to be of any real use in an emergency.
It is an object of the present invention to provide a locating system that mitigates at least some of the afore-mentioned disadvantages.
According to the present invention there is provided a microphone unit for use with a portable two-way radio transceiver, for enabling oral communication via the radio transceiver, said microphone unit including a locating device for enabling said radio transceiver to transmit a signal containing position locating information, said locating device comprising a sensor for sensing a signal containing position locating information, a memory for storing position locating information obtained from said signal, a communications device for communicating with said radio transceiver, a control device for controlling said radio transceiver via said communications device and an activating means for activating said locating device, the arrangement being such that when the locating device is activated, said control device causes said radio transceiver to transmit a locating signal containing the position locating information stored in said memory.
The invention provides a microphone unit that can be connected to a conventional handportable radio transceiver, which enables the transceiver to transmit a locating signal containing position locating information. The location of the transceiver from which the locating signal was sent can thus be easily determined, allowing help to be sent quickly. Because the locating device is connected to an existing handportable radio, a separate radio transmitter is not required and the system is thus very economical and users of the system are not required to carry additional items of equipment. Radio type approval is also not required and relatively high power radio transmitters can be used, thus minimising the necessary infrastructure. The microphone unit may be used as a replacement for a conventional microphone/loudspeaker unit.
Advantageously, the arrangement is such that when the locating device is activated, the control device causes said radio transceiver to transmit an alarm signal. The alarm signal may be transmitted simultaneously with the signal containing position locating information or separately therefrom. For example, the alarm signal may be transmitted first and the signal containing position locating information may be transmitted later, when demanded by the receiver of the alarm signal.
The sensor may be adapted to receive a signal containing position locating information from a local transmitter. The sensor may be adapted to receive an infrared signal, an ultrasound signal, an inductive signal, an electrostatic signal or an electromagnetic signal, for example a HF, UHF or VHF radio signal.
Alternatively, the sensor may be adapted to receive a plurality of signals from remote transmitters and to derive position locating information from those signals. For example, the position locating information may be derived from GPS signals or by means of interferometry.
The activating means may comprise a switch provided on the locating device, a remote switch having means for transmitting an activation signal to the locating device, means for sensing unauthorised removal of the locating device, means for sensing excessive movement, lack of movement and/or tilting of the locating device, means for sensing an activating signal transmitted to the locating device from a remote transmitter, either directly or via the radio transceiver, or any combination of these.
The locating device may be arranged to cause the radio transceiver to transmit audio activity automatically in the event of said locating device being activated, and may include means for recording audio activity taking place prior to activation.
The locating device may include means for storing an identification signal identifying said locating device, the arrangement being such that when the locating device is activated, the communications device causes the radio transceiver to transmit a locating signal containing said identification signal.
According to a further aspect of the present invention there is provided a locating system including a microphone unit as described above and a plurality of transmitters, each transmitter being arranged to transmit a signal containing position locating information. The system may also include a central station for receiving locating signals and/or alarm signals. Alternatively or in addition, each locating device may be arranged to receive locating and/or alarm signals transmitted by other locating devices.
A preferred embodiment of the invention provides a device which can, when connected to the existing two way personal radio, provide that two way radio with, as a minimum, all of the features of the prior art. Furthermore, because the existing transmitter and receiver within the two way radio are used, the technology required and hence the cost of the features is significantly reduced. Because there is no need to modify the existing equipment the issue of invalidating product type approval is avoided.
A further advantage is that the power of the transmitters used in two way personal radio equipment is generally much higher, since the regulations permit this. Large sites such as shopping areas are therefore easily protected at very reasonable cost.
Other methods of identifying the location of an individual which rely upon some form of processing within the device held by the individual include the well known Global Positioning System (GPS), and more recently interferometry techniques have been introduced. One technique, known as Cursor, is disclosed by Duffett-Smith and Woan and has a variant called High Precision (HP) Cursor. These and any future location technologies are readily incorporated with this new invention.
The present invention therefore provides a significant improvement in the scope of application of the existing prior art and other methods of location identification.
Many individuals who are responsible for the security of a building or similar facility, or who work alone, carry two way personal radios to enable them to contact their control centre or another party in the event that they require assistance or need to simply provide periodical communication to confirm their location and good health.
A disadvantage with this technique is that the location reporting is very much dependent upon the skill of the individual to know where they are. The technique also relies upon the individual being able to report this information, something they may not be able to do in the event they are incapacitated or being threatened by another individual.
The prior art technology can be (and in some cases has been) incorporated within the two way personal radio but this almost always results in some kind of performance compromise. In addition, because this means of implementation is complicated and relatively difficult to produce such systems are generally very expensive when compared with standard two way personal radios.
A further problem is that such location based two way radios are generally not compatible with any existing two way radio system infrastructure which may be in place. In addition, in the event that a more effective location technology is developed, it is not easy to upgrade the system as required: the entire system has to be replaced.
The present invention provides a very cost effective solution for these problems which also enables existing radio system to be upgraded very simply and cost effectively. The concept of the invention can easily be applied to other communication devices such as cellular radios and mobile radios installed within vehicles.
Virtually all types of personal radio available include a facility to connect an optional remote lapel microphone/loudspeaker unit (sometimes referred to as an accessory connector). Such lapel microphone/loudspeaker units also include a switch to activate the transmitter when the user wishes to speak.
This external lapel microphone/loudspeaker unit enables the user to keep their portable radio on their hip, waist or covertly hidden. A further benefit is that such an option provides protection for the user""s head from the electromagnetic signal generated by the radio transmitter aerial, a subject of some concern in recent times.
The connection style and format for these lapel microphone/loudspeaker units is usually specific to the manufacturer, but common for each version of radio. The connections provided are usually as a minimum:
signal wires for the lapel loudspeaker,
signal wires for the lapel microphone, and
signal wires for the press to talk or transmit switch
An embodiment of the present invention provides a special version of the optional lapel microphone/loudspeaker unit (hereinafter referred to as the xe2x80x9clapel unitxe2x80x9d), which includes circuitry that has the ability to determine the location of the lapel unit and enable the user to send voluntary or involuntary alarms.
In the event that the version of personal radio for which the lapel unit was designed did not provide any electrical power at the lapel unit connecting point then an integral power supply (such as a battery) would also be included.
Inclusion of a microcontroller and modem technology, the principle of which is well known, would enable the central control system to communicate with the lapel unit (or vice versa) either automatically or as a result of manual intervention on the part of the person using the lapel unit.
The exact nature of the location technology incorporated within the lapel unit would depend upon the needs of the customer. Typical situations in which the invention may be used include:
An individual who works within a building and has to patrol the various locations within that building on a regular basis.
An individual who has to patrol an area outside a building or a mixture of outside and within a building or buildings
An individual who has to work alone in wide area open spaces, such as a farmer.
An individual who has to work in a situation represented by any combination of the above.
Different technology works better in different situations. Ericsson, Tunstall and Shorrock describe technology which works very well within buildings. The preferred method described utilises electromagnetic/inductive coupling at typically 150 KHz. This is because this technology has the ability to penetrate clothes which may cover the alarm transmitter worn by the person being protected.
A disadvantage with this method, which is described by the Tunstall document, is that the signal is capable of penetrating walls, floors and ceilings. The use of infrared is not recommend because it is relatively poor at penetrating clothing.
An advantage with the lapel unit is that such units are worn externally in order for the user to be able to hear any message which may be sent via the speaker unit. Since the lapel unit is not covered, infrared can therefore be used as one method of internal location identification with a high degree of success. Localised infrared transmitting beacons can then be deployed to identify the required areas. Ultrasound based location beacons could also be used for the same reasons.
The use of inductive coupling for outside applications is not very effective, principally because the range of these location transmitters is generally very limited at typically five meters. A much better alternative would be to use higher frequency VHF or UHF low power transmitters, the preferred operating frequency being in the 170 MHz to 900 MHz range. These devices have a range of typically 50 to 100 meters and can be easily adjusted to provide a range to suit the location concerned. A compatible receiver would be fitted within the lapel unit.
The low power UHF/VHF location beacons can easily be installed in external locations such as the periphery of a building, the propagation of the signal being controlled in such a manner that the signal does not penetrate the building and confuse the system. An advantage with the low power VHF/UHF location beacons is that they are very efficient and do not require much power. This would enable the location transmitter to be powered by battery for a significant period of time, typically one year or more.
The location beacon could also incorporate a low battery alarm which could be relayed to the control system to advise when the battery requires replacing. This again results in very cost effective installation because wiring to provide power to the location transmitter is not required. In instances where the ambient light was known to be dependable solar power could be used to eliminate the need to change batteries.
For larger areas such as open fields the lapel unit could incorporate a GPS receiver. At the present time GPS receivers require a relatively high amount of power, as technology advances however this will not continue to be a significant issue and the incorporation of GPS technology with a lapel unit would be practical and cost effective.
Until such time as the GPS unit is sufficiently small enough and power requirements are sufficiently low enough for such integration the GPS unit could be carried in a separate unit which can by means of using the location receive data path transmit the GPS location data to the lapel unit for re-transmission by the personal radio. This would be particularly useful in a vehicle where the GPS module would be separate and the location data passed to the lapel unit whilst this was at rest on the dashboard. In such instances location data transfer could be either by low power radio or infrared, for example.
An alternative would be to incorporate a receiver within the lapel unit to receive the signals from the HP Cursor technology, an alternative to GPS. The resulting data could then be transferred to a central computer to enable the position of the individual to be determined. At present the HP Cursor technology provides reliable positional accuracy of typically 1 meter.
As the HP Cursor technology improves, it will no doubt be possible to achieve greater positional resolution thereby avoiding the need to use internal location beacons. The system software would however need to determine the general route of an individual in order to identify which side of a wall a person may be, for example. Alternatively, a small number of fixed beacons could be used to assist in the identification of floors, these beacons also assisting in the dynamic calibration of HP Cursor since their fixed location would be a constant.
As and when alternative location determining technology which requires some form of sensor at the portable equipment in order for the location to be determined is developed, the appropriate processing circuitry could be incorporated within the lapel unit to enable existing personal radio equipment to benefit from such advances in technology without modification.
In a similar manner, the lapel unit can incorporate any combination of the described location technology in order to provide the most effective solution.
The capability of the invention to receive and process large area based location technology also permits a further application of the invention for the purpose of determining the location of vehicles. Vehicles which utilise two way radio systems can also suffer from the previously described problems associated with providing such radio equipment with location based technology.
In this instance a separate GPS based location determining module could transfer the location data to the microphone unit for transmission to a central computer by means of the two way radio within the vehicle. Because of the very short range within the vehicle, infrared would be the preferred method to transfer location data from the GPS receiver to the microphone unit.
Once again it can be seen the invention permits very cost effective upgrade of existing radio installations to enable valuable additional facilities to be provided with ease.
Once the required location technology has been implemented, it is very easy to include additional features such as a panic button which the user can press when assistance is required in the event of an emergency. Further features would include a facility to detect the forced removal of the lapel unit from the wearer, and a mechanism to detect that the wearer has stopped moving, has fallen over, or is running. The system could also include a facility to check the correct functioning of the entire system on a periodical basis.
A particular problem which exists for sensitive situations such as prison officers is that the very act of being seen to activate the panic switch can provoke attack. If the version of lapel unit with a VHF/UHF receiver is used (as when detecting VHF/UHF location beacons) then the user could be provided with a miniature panic transmitter which could be disguised as a key fob and kept in the pocket or as a piece of jewellery such as a ring worn on the finger.
The covert activation of such a low power transmitter would be detected by the lapel unit as a special alarm code and would therefore command the portable transmitter to send the appropriate alarm signal to the control room.
Another useful feature in sensitive situations would be the ability to record the audio sounds which took place in the time prior to the alarm being raised. Such microchip recording technology is well known, and could be incorporated within the lapel unit with the ability for the central controller to control the replay of the recorded audio. The sensitivity of the microphone could be controlled to enable any audio within the general area of the lapel unit to be transmitted back to the control room.
Once the alarm and location information has been received at the central equipment it can then be processed as required. This processing may be by action of a human operator, or automatically by means of a computer system which having processed the alarm and location information could arrange for the appropriate pre recorded alarm and location messages to be broadcasted to other individuals capable of rendering assistance. Should these other individuals also have the lapel unit with location technology the system could advise which individuals were most appropriately located to render assistance soonest.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.